[arch-proaudio] package gcr breaks real-time settings

[Ralf Mardorf]

On Sun, 2018-09-02 at 13:15 +0200, David Runge wrote:
> Where exactly is that problem reported?

An Ardour 5.8.0 window informs about the issue, when starting ardour.
I'm not using Ardour from the repository, since I not always upgrade
audio software during an audio production.

> Which are your user's groups?

$ groups
wheel games video audio optical storage power users vboxusers wireshark
rocketmouse vmanusers

> Which is your user's default group?

$ id -g
1000
$ id -gn
rocketmouse

> Do you have any other files in /etc/security/limits.d?

$ ls -l /etc/security/limits.d/
total 4
-rw-r--r-- 1 root root 45 Sep  2 11:47 10-gcr.conf
$ ls -l /etc/security/
total 40
-rw-r--r-- 1 root root 4564 Jun 22 10:21 access.conf
-rw-r--r-- 1 root root 3635 Jun 22 10:21 group.conf
-rw-r--r-- 1 root root 2081 Apr 12  2013 limits.conf
-rw-r--r-- 1 root root 1835 Jun 22 10:21 limits.conf.pacnew
drwxr-xr-x 2 root root 4096 Sep  2 11:47 limits.d
-rw-r--r-- 1 root root 1440 Jun 22 10:21 namespace.conf
-rwxr-xr-x 1 root root 1016 Jun 22 10:21 namespace.init
-rw-r--r-- 1 root root 2972 Jun 22 10:21 pam_env.conf
-rw-r--r-- 1 root root 2179 Jun 22 10:21 time.conf

> What was your claimed fix?

Commenting out '@users - memlock 1024'. 

$ cat /etc/security/limits.d/10-gcr.conf 
#@users - memlock 1024

# vim:set ft=limits:
$ tail -2 /etc/security/limits.conf
@audio 	- rtprio 	99
@audio 	- memlock 	unlimited

> While all files below /etc/security/limits.d are read in C locale
> ordering, this would mean, that 10-gcr.conf is read first and
> 99-realtime-privileges.conf pretty much last.
> However, neither `man 5 limits.conf` nor `man 8 pam_limits` states the
> behavior of a user being in two different groups with diverging
> settings. I hope that's not undefined... ;-)

So the issue seemingly is, that I use /etc/security/limits.conf and not
/etc/security/limits.d/99-foo.conf.
              ^^^^^^^^^^^

My bad.

Regards,
Ralf